The promise also dropped "renewable" from the government's agenda, paving the way for a controversial switch to nuclear energy, backed by Howard as a greenhouse-friendly alternative.

"It will drive additional investment in renewable energy and other low-emissions electricity generation. This will reduce costs for business, and ultimately for households," Howard said, promising to roll state and national schemes into one.

But environment group Greenpeace said the target only streamlined existing state-based schemes, leaving sunny Australia lagging behind renewable energy leaders such as Germany and Spain, which are harnessing solar and wind power.

Howard, 68, is expected to call a national election within weeks and is polling well behind the opposition Labor Party, whose leader Kevin Rudd has pledged to sign the Kyoto Protocol capping greenhouse gas emissions in 35 developed nations.

A long-running drought in much of Australia and warnings by international scientists about the impact of global warming have spooked voters and elevated climate change to an election-turning issue.

A Galaxy poll on Monday had Labor 12 points in front of the government, 56 to 44, which would hand a landslide election victory to the youthful Rudd.

Rudd, who is this week tipped to unveil a renewable energy target of 20 percent, also won backing at the weekend from former US vice-president and climate change campaigner Al Gore.

Australian Greens Senator Christine Milne said Howard's clean target of 30,000 gigawatt hours each year did not add up and was just 9 percent of demand projected by the government's official commodities forecaster to reach 342,000 GWh in 2019.

"Around the world, the renewable energy industry is booming. In Australia, where we have tremendous resources and world-leading researchers, our industry is stalling," Milne said. (US$1=A$1.15)